Stroke: Excessive sleep may raise risk by 85%

Stroke is one of the leading causes of death and disability worldwide and in the United States, specifically. New research finds that excessive sleep considerably raises the risk of this cardiovascular problem.

Globally, 15 millionTrusted Source people experience a stroke each year. Almost 6 million of these people die as a result, and 5 million go on to live with a disability.

The list of traditional risk factorsTrusted Source for stroke is long, ranging from elements of lifestyle, including smoking, to preexisting conditions, such as diabetes.

More recently, researchers have started exploring sleep duration as another potential risk factor. Some studiesTrusted Source have found that either too much or too little sleep can increase the risk of cardiovascular events, including stroke.

According to these findings, regular sleep deprivation and sleep for more than 7 hours per night are each associated with a higher risk of stroke.

Now, a study appearing in the journal Neurology finds an association between daytime naps, excessive sleep, and stroke risk.

Dr. Xiaomin Zhang, from Huazhong University of Science and Technology, in Wuhan, China, is the corresponding author of the paper that details this study.

85% higher risk in long sleepers, nappers

Dr. Zhang and the team collected information from 31,750 people in China. None of the participants — who were 62 years old, on average — had a history of stroke or any other serious health condition at the start of the study.

The participants answered questions about their sleeping patterns and napping habits, and the researchers clinically followed the group for an average of 6 years.

The team found that 8% of the participants were in the habit of taking naps that lasted longer than 90 minutes, and 24% reported sleeping for at least 9 hours each night.

Over the study period, there were 1,557 strokes among the participants. Those who slept for 9 or more hours per night were 23% more likely to experience a stroke than those who regularly slept only 7–8 hours each night.

People who got less than 7 hours of shuteye or 8–9 hours had no higher risk of stroke than those who slept 7–8 hours.

Importantly, people who both slept for longer than 9 hours and napped for more than 90 minutes per day had an 85% higher risk of stroke than those who slept and napped moderately.

Finally, sleep quality to play a role — people who reported poor sleep quality were 29% more likely to have a stroke than those whose sleep quality was reportedly good.

These results continued to be significant after adjusting for potential confounders, such as hypertension, diabetes, and smoking.

“These results highlight the importance of moderate napping and sleeping duration and maintaining good sleep quality, especially in middle-age and older adults.”